Jesus christ... has anyone reliably solved the issues of weak growth in early veg under LED? What's the answer????

[Prawn Connery]

The contribution of CalMg to Nitrogen levels is minimal.

For example, GH CalMagic has 1% Nitrogen, or 3 ppm N per ml/G.

Percentages don't mean much – it's the ratios that count.

You can add as little or as much Calmag as you like, but most of the good ones are made of calcium nitrate and magnesium nitrate that have similar N Ca Mg ratios. Calcium nitrate has a ratio of rougly 3 parts Ca to 2 parts N, and Magnesium nitrate is roughly 1 to 1. They all have chelated iron and some have boron and other metals.

Popular Calmag brands = N Ca Mg ratios
Canna Calmag Agent = 2/4/1.2
GH Calimagic = 1/5/1.5
Botanicare = 2/3.2/1.2
Flairform CMX = 4/6/2

Check you local hydro shop. Your mileage may vary.

 

[Billy the Mountain]

GH Calmagic has 1%N, 5%Ca, and 1.5% Mg fwiw (~3:1 Ca to Mg)

Ratios aside, it's still a minimal source of Nitrogen in a nute mix (3ppm N per ml/G); a good thing imho.

 

[Prawn Connery]

GH Calmagic has 1%N, 5%Ca, and 1.5% Mg fwiw (~3:1 Ca to Mg)

Ratios aside, it's still a minimal source of Nitrogen in a nute mix (3ppm N per ml/G); a good thing imho.

Nearly all brands of calmag have a Ca:Mg ratio of 3:1 There is a reason for that I won't go into here.

My base veg nutrient has the following concentations:
2.2% N, 0.57% P, 2.7% K

The calmag I use has the following concentrations:
3% N, 3% Ca, 1% Mg

(Coincidentally, if you add two parts of calcium nitrate to one part magnesium nitrate you get 3 3 1 ratios of N Ca Mg)

So my calmag actually has more N than my base nutrient. Can you please explain how that works? I suspect you know where I'm going wth this . . .

General Hydroponics CaliMagic is really only one brand, and it happens to have the least amount of nitrogen it is. They may use a combination of calcium/magnesium nitrate and calcium/magnesium carbonate to get the N levels down. Maybe they use a bit of epsom (I dont know, I've never used it). EDIT: I just looked up the ingredients and in fact they do use Epsom and calcium carbonate.

All the other brands I listed have higher concentrations of N and so can be a significant source of nitrogen when used.

But back to my question . . . If I add 6 parts base nutrient to 2 parts calmag I get the following ratios: 19.2 3.42 16.2

My nitrogen to potassium ratio has now increased from 4:5 to 5:4 simply by adding 2ml per litre of calmag to 6ml per litre of base nutrient.

If you crunch the numbers, you'll see that calmag can be a significant source of nitrogen. Again, your mileage may vary, but my statement that calmag can be a significant source of nitrogen is entirely factual.

 

[Have2]

for the ones above, hard to say this time as i tried a few rounds half assed organic growing.
had been recylced and recharged soil, was/is a lot EWC in it and other stuff.
well, they had been well feed at that point for sure seeing their green.
will do more with salt soon again, but as i grew so much in soil with EWC and organic fert pellets recently i hesitate to throw out a number... but may would give them 1.5 (IF it was a salt grow).

What is the tool you're using for spectrum / umol ? seems nice =)

 

[Star Dog]

T5s are inefficient, so act as a heater. If you replacd the light intensity but don't adjust for the lower temps you're not comparing apples to apples. It is just more complex than replacing one light with the next and then blame the changed (worsened) environment on the lighting technology.

I get what you're saying but the difference between t5s and led in summer is about 3c so 25/26c, ime that's ample for healthy growth if not the quickest in the world.

I get satisfactory growth rates with considerably less than 25/26c with led.
These were growing fine at 23c

Before I removed the t5s I got a reading from the light meter then changed to 4k led at the same intensity figure.

That might not be the same temps as t5s but it's way above the threshold of poor growth.

I wasn't clear in what I was saying, the plants physically went back the way, they did not like ≈ intensity from led as t5s with suitable conditions, worst case they should've slowed growth not went back the way.

 

[Gdp1]

You might wanna reach out to @ Rurumo

 

[Star Dog]

It's odd?
if I start seeds/clones under led they're fine but for some reason the transitioning from t5s to led they don't like it to begin with?

I was looking at a old diary earlier I noted after flipping it was 10 days of dim lighting before they picked up.

 

[1212ham]

You might wanna reach out to @ Rurumo

Sadly, Rurumo was hit hard by covid and hasn't posted since spring.

 

[cobshopgrow]

What is the tool you're using for spectrum / umol ? seems nice =)

Sekonic Spectromaster C7000, bought a few years ago.

 

[Have2]

Sekonic Spectromaster C7000, bought a few years ago.

Thank you for the information!

Are you renting it?

 

[cobshopgrow]

Thank you for the information!

Are you renting it?

nope

 

[sfw1960]

nope

Yikes ~
At the price of one I can certainly see why you wouldn't!

 

[Syntax747]

Holy shit bro! Hell, I thought my Apogee MQ-500 was a bit over priced.

 

[Kola_Kreator]

Assuming that you've got pH in check Slow growth is either not enough light or nutes. T5's and HID's have a lot less usable light than LED's. You need to forget everything you did with the fluros.

To get the best out of an LED + Coco setup you want to run a blend of A + B + Cal mag at around 1.6 - 1.8 EC in veg and water every second hour the lights are on with an auto watering system. Increasing the number of feeds per day fixes pretty much everything if you are in Coco.

 

[Prawn Connery]

Assuming that you've got pH in check Slow growth is either not enough light or nutes. T5's and HID's have a lot less usable light than LED's. You need to forget everything you did with the fluros.

To get the best out of an LED + Coco setup you want to run a blend of A + B + Cal mag at around 1.6 - 1.8 EC in veg and water every second hour the lights are on with an auto watering system. Increasing the number of feeds per day fixes pretty much everything if you are in Coco.

This is good advice and one of the few times I have read where someone really gets coco. A lot of people hand-water coco and treat it like soil, but the more you treat it like hydro (which it is) the better the results. I feed my plants 6x a day – every two hours – on an atuo-watering system. Each time you water the pot gets fresh nutes as well as being flushed. But each time you water, the nutrient solution also pulls oxygen down with it into the root zone which supports rapid growth.

All I would add is that those EC levels should be on top of the water EC (soft or hard). So if your starting water is EC 0.3-0.4 then you would want a total EC of 2.0-2.2. If you use RO or demineralised water, you will usually need more CalMag to supplement, as tap water generally has a bit of calcium/magnesium carbonate (from limestone water sources) as well as traces of iron, zinc and copper form the pipes.

 

[Drop That Sound]

Bro science alert!

IMO, the plants don't really like the constant flicker that happens with most LED tech. They never seem to grow as lush no matter what.. but then again I live up north, and LED is mostly worthless except for the summer time. Glaringly bright with no warmth doesn't make much sense most of the year..

Anyway, you can tell if its happening by spinning a fidget spinner or something with a bearing really fast in front of the led lights.. if it appears to spin backwards of the direction you spun it, then you know its flickering.. which is documented to have negative effects to living things, especially people. Some more than others. Regulations in the industries only do so much to keep it at "acceptable" limits.

The driver circuits are wired differently than HID too, and radiate higher EM frequencies that saturate the entire area around the plants than the old school mag\HO flouro ballasts do. Even newer digital HID ballast put out a ton of filthy interference, and flicker too. Some brands were so bad the noise could be picked up miles away. Plants are just as susceptible to being electro-sensitive as people, and something about LEDs just doesnt vibe with the plants if you ask me..

 

[Lou66]

the constant flicker that happens with most LED tech

High power LED supplies are not PWM dimmed like many LEDs for human centric lighting (that are low power too). They don't flicker but just emmit constant light. The reason is that pulsed light appears brighter than the same energy emmited at constant level. On the other hand PWM dimming gets more difficult as current increases and circuits get larger. Parasitic inductance makes it difficult to switch high currents.

Plants are just as susceptible to being electro-sensitive as people

So... not at all?

 

[Star Dog]

I'd noticed a few likable characters weren't here anymore @Rurumo being one of them, I hope she's OK.

 

[sfw1960]

Every AC powered kind of light or electronics runs on either 50-60 Hz so ALL of them "flicker".
It's a known fact when someone visits the UK (for example) from North America they immediately notice the flickering lights because the UK uses 240 VAC/50 Hz and N. America uses 120VAC/60Hz.
Fluorescent bulbs and very noticeable to more people but they don't get a bad rap in that kind of way. ALL lighting "flickers" and always has.
PWM circuits are usually very "dirty" in their EMI or RFI output but the higher the pulse frequency the less likely you would see any flickering and it's been documented the emissions from fluorescent does affect living things including people.
I ran a communications electronics repair shop back in the late 70's - early 80's so I have a little background on it.
Not sure where any bro science is in that - but it's not likely a cause because the atmosphere is filled with human generated noises that aren't natural and it's everywhere indoors and outside too.
Utility poles with transformers @ 7200 VAC (N A.)?
One's behind our garage and the barred owls don't seem to mind...
Go listen to high power wires by a power station and you'd think anything within a mile was in a deep fryer. The critters in the area seem unaffected including deer, bald eagles and a bunch of other wildlife including the green things.
If it affects plant life I'd like to see documentation supporting the findings.
I'm with Prawn - when you employ a different method you have to change the way you go about things adapt and overcome. HID, fluorescent, LED and filament lighting is all fundamentally different. Including just color temps...

 

[DukeFluke]

T5s have an efficiency around 0,7 µmol/J, LEDs have 2-2,8 µmol/J. So for a given amount of light T5s produce 3 times the heat that an LED does.

The quantum board style LEDs are quite diffuse. They don't lose much to T5s in a real world scenario. COBs are worse of course.

Yes but the t5s are almost touching the seedlings, the led is a good bit away